Systems and methods for enhancing obstacles and terrain profile awareness

ABSTRACT

A display system for an aircraft includes a processing unit configured to receive data related to an aircraft profile and to supply display commands with symbology based on the aircraft profile; and a display device coupled the processing unit and configured to receive the display commands and operable to render a three-dimensional view with the symbology based on the aircraft profile. The symbology may include slope symbology.

TECHNICAL FIELD

The present invention generally relates to aircraft display systems andmethods and, more particularly, to systems and methods that displayimages for enhancing obstacle and terrain profile awareness.

BACKGROUND

Computer generated aircraft displays have become highly sophisticatedand capable of displaying a substantial amount of flight management,navigation, and control information that gives flight crews moreeffective control of the aircraft and a reduction in workload. In thisregard, electronic displays, such as Heads-Up Displays (HUDs) andHeads-Down Displays (HDDs), are used in aircraft as Primary FlightDisplays. For example, the Primary Flight Display can combine criticalflight instrumentation (e.g., altitude, attitude, heading, airspeed,vertical speed instruments) and primary engine instrument indicatorsinto a single, readily interpretable display.

Some Primary Flight Displays may provide a 3D, synthetic perspectiveview of the terrain surrounding the aircraft, including man-made andnatural terrain. However, computer generated, synthetic perspectiveviews may not provide a pilot with complete situational awareness.Designers are constantly attempting to enhance awareness, particularlywith respect to obstacle and terrain profiles, without unnecessarilycluttering the display.

Accordingly, it is desirable to provide systems and methods that enhanceobstacle and terrain profile awareness on a visual display, such as, forexample, a Primary Flight Display, similar electronic aircraft displays,and other types of electronic displays. Furthermore, other desirablefeatures and characteristics of the present invention will becomeapparent from the subsequent detailed description of the invention andthe appended claims, taken in conjunction with the accompanying drawingsand this background of the invention.

BRIEF SUMMARY

In accordance with an exemplary embodiment, a display system for anaircraft is provided. The system includes a processing unit configuredto receive data related to an aircraft profile and to supply displaycommands with symbology based on the aircraft profile; and a displaydevice coupled the processing unit and configured to receive the displaycommands and operable to render a three-dimensional view with thesymbology based on the aircraft profile. The symbology may include slopesymbology.

In accordance with another exemplary embodiment, a method is providedfor displaying symbology on a Primary Flight Display of an aircraft. Themethod includes determining an aircraft profile based on aircraft andflight characteristics; constructing a footprint based on the aircraftprofile; evaluating terrain slope within the footprint; and displayingsymbology based on the terrain slope within the footprint.

In accordance with yet another exemplary embodiment, a Primary FlightDisplay system for an aircraft includes a processing unit configured toreceive data related to an aircraft profile and to supply displaycommands with symbology based on the aircraft profile; and a displaydevice coupled the processing unit and configured to receive the displaycommands and operable to render the common three-dimensional view withsymbology based on the aircraft profile. The symbology includes slopesymbology and a footprint based on the aircraft profile, and thesymbology further includes obstacle warning symbology within thefootprint.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe following drawing figures, wherein like numerals denote likeelements, and wherein:

FIG. 1 is a functional block diagram of an aircraft display systemaccording to an exemplary embodiment;

FIG. 2 depicts an exemplary image that may be rendered by the aircraftdisplay system of FIG. 1; and

FIG. 3 is a flowchart describing an exemplary method for enhancingobstacle and terrain profile awareness.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. Furthermore, there is no intention to be bound by any theorypresented in the preceding background or the following detaileddescription.

Broadly, exemplary embodiments described herein provide visual displaysystems and methods for aircraft. More specifically, the visual displaysystems and methods enhance obstacle and terrain profile awareness. Forexample, the characteristics of the symbology used to representobstacles and terrain may be based on the specific profile of theaircraft and/or flight path. The symbology may include a footprint withobstacle warnings and slope indications.

FIG. 1 depicts a block diagram of an exemplary aircraft visual displaysystem 100 for displaying symbology that enhances obstacle and terrainawareness. In the exemplary embodiment shown, the system 100 includes aprocessing unit 102, a database 104, a flight management system 106, adisplay device 108, and a sensor system 110. Although the system 100appears in FIG. 1 to be arranged as an integrated system, the system 100is not so limited and can also include an arrangement whereby one ormore of the processing unit 102, the database 104, the flight managementsystem 106, the display device 108, and the sensor system 110 areseparate components or subcomponents of another system located eitheronboard or external to an aircraft. Also, for example, the system 100can be arranged as an integrated system (e.g., aircraft display system,Primary Flight Display system, a Head Up Display with SVS or EVS as anoverlay, a “near to eye display” system, or a head mounted displaysystem, etc.) or a subsystem of a more comprehensive aircraft system(e.g., flight management system, navigation and control system, targetaiming and control system, collision alert and/or avoidance system,weather avoidance system, etc.). The system 100 can be utilized in anaircraft, such as a helicopter, airplane, or unmanned vehicle. Moreover,exemplary embodiments of the system 100 can also be utilized inspacecraft, ships, submarines, fixed wing and rotor aircraft, such ashelicopters, as well as other types of vehicles. For simplicity,embodiments are described below with reference to “aircraft.”

The processing unit 102 can be a computer processor associated with aPrimary Flight Display. Generally, the processing unit 102 receivesand/or retrieves flight management information (e.g., from the flightmanagement system 106) and landing, target and/or terrain information(e.g., from database 104 or sensor system 110). The processing unit 102generates display control signals for a visual display of the flightmanagement information, which includes navigation and control symbologysuch as a zero pitch reference line, heading indicators, tapes forairspeed and altitude, flight path information, RNP information, and anyother information desired by a flight crew. As discussed in furtherdetail below, the processing unit 102 may additionally receives andintegrates terrain data from the database 104 and sensor system 110, andgenerates display control signals based on the terrain data. Theprocessing unit 102 then sends the generated display control signals toa display device (e.g., the display device 108). More specific functionsof the processing unit 102 will be discussed below.

Database 104 is coupled to processing unit 102 and can be a memorydevice (e.g., non-volatile memory, disk, drive, tape, optical storagedevice, mass storage device, etc.) that can store digital landing,waypoint, and target location as either absolute coordinate data or as afunction of an aircraft's position. Database 104 can additionallyinclude other types of navigation information, such as information usedto calculate flight path. Database 104 can also include, for example, aterrain database, which includes the locations and elevations of naturaland man-made terrain. The terrain can include obstacles, such asbuildings and vehicles. Obstacle data can be stored together withterrain database or in a separated obstacle-only database. Thegeographic locations and height of the obstacles for various avionicsapplications can be obtained through survey or through various reportingservices. Database 104 may further include slope information related tothe terrain.

The sensor system 110 is coupled to the processing unit 102 and caninclude any suitable sensor for detecting terrain and providing data tothe processing unit 102 based on the detected terrain. The sensor system110 can include sensors such as radar, LIDAR, or forward-lookinginfrared (FLIR). Other types of imaging sensors may include types suchas visible light, millimeter-wave radar, X-band weather radar, etc. Inone embodiment, the sensor system 110 is a stand-alone system, althoughin other embodiments, the sensor system 110 can be used to completely orpartially verify database 104. The sensor collected data, afteradditional verifications, may be later inserted into the database 104for future uses.

The flight management system 106 is coupled to processing unit 102, andcan provide navigation data associated with the aircraft's currentposition and flight direction (e.g., heading, course, track, etc.) tothe processing unit 102. The navigation data provided to the processingunit 102 can also include information about the aircraft's airspeed,altitude, pitch, and other important flight information. In exemplaryembodiments, the flight management system 106 can include any suitableposition and direction determination devices that are capable ofproviding the processing unit 102 with at least an aircraft's currentposition (e.g., in latitudinal and longitudinal form), the real-timedirection (heading, course, track, etc.) of the aircraft in its flightpath, the waypoints along the flight path, and other important flightinformation (e.g., pitch, airspeed, altitude, attitude, etc.). Suchinformation can be provided to the processing unit 102 by, for example,an Inertial Reference System (IRS), Air-data Heading Reference System(AHRS), and/or a global positioning system (GPS).

The system 100 also includes the display device 108 coupled to theprocessing unit 102. The display device 108 may include any device orapparatus suitable for displaying various types of computer generatedsymbols and information representing at least pitch, heading, flightpath, airspeed, altitude, landing information, waypoints, targets,obstacle, terrain, and slope data in an integrated, multi-color ormonochrome form. Using data retrieved (or received) from the flightmanagement system 106, the processing unit 102 executes one or morealgorithms (e.g., implemented in software) for determining the positionof the various types of desired information on the display device 108.The processing unit 102 then generates a plurality of display controlsignals representing this data, and sends display control signals to thedisplay device 108. The display device 108 and/or processing unit 102may include a graphics display generator for generating the appropriatesymbology on the screen of the display device 108, as discussed ingreater detail below. In this embodiment, the display device 108 is anaircraft cockpit, multi-color display (e.g., a Primary Flight Display).

Although a cockpit display screen may be used to display theabove-described flight information symbols and data, any suitable typeof display medium capable of visually presenting multi-colored ormonochrome flight information for a pilot or other flight crew membercan be provided, such as, for example, various CRT and flat-paneldisplay systems (e.g., CRT displays, LCDs, OLED displays, plasmadisplays, projection displays, HDDs, HUDs, etc.).

An exemplary visual display 200 is shown in FIG. 2. The visual display200 is an exemplary visual display that may be rendered, for example, bythe aircraft display system 100 of FIG. 1.

The visual display 200 shows, among other things, computer generatedsymbols representing a zero pitch reference line 202, an airspeed scaleor tape 204, an altitude scale or tape 206, a landing pad 208, currentposition 210, and terrain (e.g., identified generally as element 212).Although the visual display 200 is shown as an egocentric, first-personframe of reference, the visual display 200 can be a secondary, wingman,and/or plan or perspective view that enables a viewer to view theaircraft, as well as zoom in and out, including an unmanned vehicleand/or spacecraft. Although the visual display 200 is generallyassociated with a Primary Flight Display, the display can also beutilized on a multi-function display, Head Up Display, and/or a headmounted display.

In this embodiment, the terrain 212 is rendered as a three-dimensional,perspective view. The terrain 212 can include any representation of theenvironment surrounding the aircraft, including flattened terrain.Additionally, the terrain 212 can include a virtual plane selected by apilot at certain elevation relative to the aircraft and is rendered atthat elevation.

In addition, and as will now be described in more detail, the visualdisplay 200 may selectively render symbology and/or adjust symbologybased on the profile of the aircraft. The profile of the aircraftincludes both characteristics of the aircraft itself, the flight path ofthe aircraft, and/or the current energy of the aircraft, the intendedtarget or destination location.

In the depicted exemplary embodiment, the visual display 200 indicates afootprint 250 of the aircraft. As a general matter, the footprint 250generally corresponds to the path of the aircraft and may include thearea underneath, around, and in front of the aircraft. The size of thefootprint may be a function of the profile of the aircraft, as notedabove, and may particularly consider the span of the aircraft, theflight path, and the speed of the aircraft. The footprint 250 may beindicated by an enhancement of the displayed symbology, a change incolor, and/or a change in texture. In one embodiment, the terrain 212within the footprint 250 has a higher resolution than the terrain 212outside of the footprint 250.

The visual display 200 may further include slope indication 260 in thefootprint 250. The slope indication 260 may include an indication of therelative slope of the terrain within the footprint 250. The slopeindication 260 may particularly give the pilot an indication of when theslope may be a problem for the aircraft, i.e., a warning. In thedepicted embodiment, the slope indication 260 includes a change inrelative color. For example, a first color (e.g., beige) 262 indicatesrelatively higher terrain, and a second color (e.g., dark green) 264indicates relatively lower terrain. The slope indication 260 may furtherinclude a slope scale 266. The slope scale 266 includes a directionalindicator 268, which indicates the direction of the slope by pointing ina downhill direction and may further match the relative colorsadditionally displayed by on the terrain 212. In other words, the rightside of the directional indicator 268 may be in the first color (e.g.,color 262) and the left side of the directional indicator 268 may be inthe second color (e.g., color 264). The slope indication 260additionally includes a slope quantity 270 of 10° to further provide aspecific value of the slope.

In further exemplary embodiments, the appearance of the landing pad 208may change to provide additional slope indication. For example, one sideof the landing pad 208 may be stretched out to indicate the direction ofslope. The outline of the profile and landing pad 208 may changeappearance when slope or obstacle protrusions present dangers.

The visual display 200 further includes enhanced obstacle awareness inthe footprint 250 for obstacles that may present an issue for theaircraft. As an example, terrain feature 280 is in the landing pad 208of the aircraft, and may have a height that interferes with the landingprocedure, cause the aircraft to tip over, and/or strike a wing orrotorblade. As such, the terrain feature 280 is rendered with a warningcharacteristic. In this case, the terrain feature 280 may be rendered ina warning color, such as red. The warning characteristic of the terrainfeature 280 may further include a blinking action and/or a change intexture. As noted above, the number of terrain features with enhancedobstacle awareness and/or the nature of any warning characteristics maybe a function of the profile of the aircraft.

As noted above, the rendered symbology and/or adjusted symbology arebased on the profile of the aircraft. For example, the profile may be asimple circle marching rotor size for a helicopter or may include addedsize or changed shape when there are cross winds which may cause theaircraft to drift. Additionally, some of the profile tracing lines canbe added inside the profile to further highlight the terrain or obstacleprofile relative to the aircraft profile or foot print. For example thetriangle within landing pad 208 indicates the wheel areas for ahelicopter. Although the symbology indicates that at least some of theterrain in the landing pad 208, the line profile represents the relativeflatness or the area, with the exception of terrain feature 280.

FIG. 3 is a flow chart that depicts a method 300 for enhancing obstacleand terrain profile awareness in 3D, synthetic view for a Primary FlightDisplay of an aircraft, such as for example, the system 100 discussedabove. As such, the method 300 of FIG. 3 will be described withreference to FIG. 1.

In a first step 305, the processing unit 102 receives data from thedatabase 104, flight management system 106, and/or sensor system 108.The processing 102 then determines a footprint (e.g., footprint 250)corresponding to the aircraft profile, including the aircraft and flightcharacteristics.

In second step 310, the processing unit 102 evaluates obstacles in thefootprint based on the aircraft profile. In a third step 315, theprocessing unit 102 enhances the symbology for any obstacle that maypresent a problem for the aircraft. For example, the processing unit 102may provide warning symbology for such obstacles.

In a fourth step 320, the processing unit 102 evaluates the slope withinthe footprint, and in a fifth step 325, the processing unit 102 providessymbology that indicates the slope evaluation. The slope symbology mayinclude color changes and/or graphical slope indicators. In a sixth step330, the processing unit 102 generates display command signals based onthe symbology such that a visual display (e.g., visual display 200) maybe provided on the display device 108.

Accordingly, the system 100 and the method 300 may enhance obstacle andterrain profile awareness. Particularly, exemplary embodiments mayinclude the following enhancements: enhanced awareness of terrain andobstacle field fluctuations within an operational footprint of theaircraft by color encoding obstacle height fluctuations beyond apredetermined height limit profile for the safe operation; use of colorcoding to precisely indicate the limit of a safe operating profile;using terrain tracing lines to indicate the terrain profiles along theoperating footprint and the landing pad; color coding terrain featuresto indicate an unsafe condition; a graphic icon displaying precisesloping and orientation of the terrain profile the landing pad; andslope direction indications.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention. It being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims.

1. A display system for an aircraft, comprising: a processing unitconfigured to receive data related to an aircraft profile and to supplydisplay commands with symbology based on the aircraft profile; and adisplay device coupled the processing unit and configured to receive thedisplay commands and operable to render a three-dimensional view withthe symbology based on the aircraft profile, the symbology comprisingslope symbology.
 2. The display system of claim 1, wherein the symbologyincludes a footprint based on the aircraft profile, and wherein theslope symbology is provided within the footprint, the slope symbologyincluding terrain tracing lines.
 3. The display system of claim 2,wherein the footprint has a different color or texture relative to anysurrounding symbology.
 4. The display system of claim 1, wherein theslope symbology includes a first color for a first elevation and asecond color for a second elevation.
 5. The display system of claim 1,wherein the slope symbology includes at least two colors indicatingrelative elevation.
 6. The display system of claim 1, wherein the slopesymbology includes a slope indicator.
 7. The display system of claim 6,wherein the slope indicator includes an arrow pointing in a slopingdirection.
 8. The display system of claim 7, wherein the arrow is colorcoded.
 9. The display system of claim 6, wherein the slope indicatorprovides a numerical indication of the slope.
 10. The display system ofclaim 2, wherein the footprint includes a landing pad.
 11. The displaysystem of claim 2, wherein symbology includes obstacle warning symbologywithin the footprint.
 12. The display system of claim 11, wherein theobstacle warning symbology includes a warning color.
 13. The displaysystem of claim 1, wherein the aircraft profile includes aircraftcharacteristics.
 14. The display system of claim 1, wherein the aircraftprofile includes flight characteristics.
 15. The display system of claim1, wherein the display device is a Primary Flight Display (PFD).
 16. Amethod for displaying symbology on a Primary Flight Display of anaircraft, comprising: determining an aircraft profile based on aircraftand flight characteristics; constructing a footprint based on theaircraft profile; evaluating terrain slope within the footprint; anddisplaying symbology based on the terrain slope within the footprint.17. The method of claim 16, wherein the displaying step includesdisplaying symbology in a first color for a first elevation and in asecond color for a second elevation.
 18. The method of claim 16, whereinthe displaying step includes displaying symbology that includes a slopeindicator with an arrow pointing in a downhill slope direction.
 19. Themethod of claim 16, wherein the displaying step includes displayingsymbology that includes obstacle warning symbology within the footprint.20. A Primary Flight Display system for an aircraft, comprising: aprocessing unit configured to receive data related to an aircraftprofile and to supply display commands with symbology based on theaircraft profile; and a display device coupled the processing unit andconfigured to receive the display commands and operable to render thecommon three-dimensional view with symbology based on the aircraftprofile, the symbology comprising slope symbology and a footprint basedon the aircraft profile, the symbology further including obstaclewarning symbology within the footprint.